Percent free prostate specific antigen in the total prostate specific antigen 2 to 4 ng./ml. range does not substantially increase the number of biopsies needed to detect clinically significant prostate cancer compared to the 4 to 10 ng./ml. range
Percent free prostate specific antigen in the total prostate specific antigen 2 to 4 ng./ml. range does not substantially increase the number of biopsies needed to detect clinically significant prostate cancer compared to the 4 to 10 ng./ml. range
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DOI：
10.1016/s0022-5347(05)64668-x
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发表时间：
2002-08-01
影响因子：
6.6
通讯作者：
Partin, AW
中科院分区：
文献类型：
--
作者：
Haese, A;Dworschack, RT;Partin, AW
目的：游离前列腺特异性抗原（PSA）对选择总PSA为4 ~ 10 ng /ml的前列腺活检患者有用。然而，20% PSA在2.6到4毫微克/毫升之间的男性。有明显的前列腺癌和游离PSA的百分比被建议在PSA总范围内帮助决定活检。人们担心，在这个范围内发现1个癌症所需的活检次数可能过高。在前瞻性转诊人群中，我们评估了各种游离PSA临界值的敏感性和特异性，并确定了PSA 2至4 ng /ml的每癌活检率。并根据Gleason评分报告所发现癌症的生物学性质。将结果与参考组患者的结果进行比较（PSA为4至10 ng./ml）。（良性直肠指检）来自同一前瞻性转诊队列。材料与方法：测定总PSA和游离PSA，计算游离PSA百分比。在最初的1,602名男性中，756人进行了直肠指检，PSA为4至10 ng /ml。219例经直肠指诊，PSA为2 ~ 4 ng /ml。确定敏感性、特异性、真阳性（癌症证据）和假阳性（无癌症证据）活检的数量。真阳性活检与所有活检的比率用于确定每癌活检的比率。对检测到的肿瘤进行格里森评分。重复上述步骤测定PSA 4 ~ 10 ng /ml。范围内。结果：PSA为4 ~ 10 ng /ml。当游离PSA为18% ~ 25%时，敏感性为63.7% ~ 92.5%，特异性为57.5% ~ 18.7%。平均需要3次活检才能发现1例癌症。当PSA为2 ~ 4 ng /ml时。当检测相同的游离PSA临界值时，敏感性为46.3% ~ 75.6%，特异性为73.6% ~ 37.6%。计算每个癌症的活组织检查的比率为各种百分比的游离PSA切断显示，需要3至5活检才能发现1个癌症。在PSA检测到的41种癌症中，2 ~ 4 ng /ml。6号靶场的格里森评分为5分。大多数病例（41例中有28例）Gleason评分为6分。Gleason评分5例为7分，1例为8分。结论：PSA在4 ~ 10 ng /ml。前列腺癌检测的范围高灵敏度是至关重要的，检测1例癌症需要3次活检。PSA为2 ~ 4 ng /ml。游离PSA的临界值为18%至20%，可检出约50%的癌症，同时节省高达73%的不必要活组织检查，活组织检查与癌症的比例为3:1。百分比游离PSA可适用于PSA 2至4 ng./ml。检测前列腺癌的范围，仅适度增加了检测1个重大癌症所需的活检次数，而大于4至10 ng /ml。范围内。
Purpose: Percent free prostate specific antigen (PSA) is useful to select patients for prostate biopsy with total PSA 4 to 10 ng./ml. However, 20% of men with PSA between 2.6 and 4 ng./ml. harbor significant prostate cancer and percent free PSA has been suggested to aid in the decision to biopsy in this total PSA range as well. Concerns exist that the number of biopsies needed to detect 1 cancer in this range may be inappropriately high. In a prospective referral population we evaluated sensitivity and specificity of various percent free PSA cutoffs and determined the biopsy-per-cancer ratio in the PSA 2 to 4 ng./ml. range in men with a benign digital rectal examination, and report on the biological nature of the detected cancers based on Gleason score. Results were compared to those obtained from a reference group of patients (PSA 4 to 10 ng./ml., benign digital rectal examination) from the same prospective referral cohort.Materials and Methods: Total PSA and free PSA were measured and percent free PSA was calculated. Of the initial 1,602 men 756 had a benign digital rectal examination and PSA 4 to 10 ng./ml., and 219 had a benign digital rectal examination and PSA 2 to 4 ng./ml. Sensitivity, specificity, the number of true positive (evidence of cancer) and false-positive (no evidence of cancer) biopsies were determined. The ratio of true positive biopsies-to-all biopsies performed was used to determine the biopsy-per-cancer ratio. Gleason score of the detected cancers was evaluated. The procedure was repeated for the PSA 4 to 10 ng./ml. range.Results: In the PSA 4 to 10 ng./ml. range a sensitivity of 63.7% to 92.5% with a specificity of 57.5% to 18.7% was found when percent free PSA was 18% to 25%. On average 3 biopsies were needed to detect I cancer. When PSA was 2 to 4 ng./ml. sensitivity was 46.3% to 75.6% and specificity was 73.6% to 37.6% when the same percent free PSA cutoff was examined. Calculation of the biopsy-per-cancer ratio for various percent free PSA cutoffs revealed that 3 to 5 biopsies were needed to find 1 cancer. Of 41 cancers detected in the PSA 2 to 4 ng./ml. range 6 had a Gleason score 5. The majority (28 of 41) of cases had a Gleason score of 6. Gleason score was 7 in 5 patients and 8 in 1.Conclusions: In the PSA 4 to 10 ng./ml. range high sensitivity for prostate cancer detection is critical and 3 biopsies are needed to detect 1 cancer. In the PSA 2 to 4 ng./ml. range a percent free PSA cutoff of 18% to 20% detected about 50% of cancers while sparing up to 73% of unnecessary biopsies with a biopsy-to-cancer ratio of 3 to 4:1. Percent free PSA can be applied to the PSA 2 to 4 ng./ml. range to detect prostate cancer and only moderately increases the number of biopsies needed to detect 1 significant cancer compared to the greater than 4 to 10 ng./ml. range.